Which of the following accurately describes waveform monitors?

Waveform monitors are essential tools in the field of video production, primarily used to analyze and monitor the video signal's characteristics. When describing their function, they serve to diagnose issues related to video signals and equipment performance, making option B an accurate description.

Waveform monitors provide visual representations of the video signal's amplitude over time, enabling professionals to assess aspects such as brightness, contrast, and color balance. This capability is vital for ensuring that the video output meets broadcasting standards and resolves any potential discrepancies in the video signal. By using a waveform monitor, operators can make critical adjustments to camera settings, color correction, and post-production processes, thereby enhancing overall production quality.

In contrast, the other options highlight functions not associated with waveform monitors. They do not specifically record broadcast signals directly nor generate 3D video outputs. Additionally, waveform monitors are not limited to audio production, as their primary focus is on visual signal analysis. This underscores the specialized role waveform monitors play in the broader context of video production and equipment management.